The basis of medical imaging is the measurement of a property of tissue that varies with tissue composition. Medical images are formed by displaying intensities as a function of these properties measured at multiple locations in the body. Mechanical properties of tissue are important indicators of disease potential. Indeed, palpation techniques are commonly used by medical doctors to determine the potential for disease, for example, stiffer tissue regions that can be felt as harder objects can indicate the presence of cancer. This is the basis for a number of clinical examinations such as the digital rectal examination for prostate cancer or bimanual exam for ovarian cancer. However, a need for improved medical imaging of tissue exists.